While Marchionne has not given up on the idea of luring GM to the bargaining table through shareholder pressure, his camp knows that they need to explore more options because GM CEO Mary Barra and her board have stonewalled him, the people said. Marchionne said in an interview that he prefers a friendly deal if he can get one, particularly with an automaker that has a similar product range, providing more opportunities for cost-saving.

A merger between FCA and GM is largely the brainchild of Marchionne himself. He wants to rid the global auto market of redundancies in manufacturing, since plenty of automakers make essentially the same vehicles.

General Motors CEO Mary Barra has acknowledged being approached by GM, but said her board had no interest in the offer.

Fiat Chrysler’s stock has steadily risen since its 2014 IPO, currently sitting at almost $US16, higher than its initial asking price of $US11.